And so, after a solid week of me picking Carper every day in the gay-marriage pool as the next Democrat to flip, only to be disappointed every time, he finally flips … the day after I switch my pick to Bill Nelson.

Congrats to JohnGalt23 for scooping up Carper after I dropped him. See why I don’t bother filling out NCAA Tournament brackets anymore?

As our society has changed and evolved, so too has the public’s opinion on gay marriage – and so has mine. I pray every day for God to grant me the wisdom to do what is right. Through my prayers and conversations with my family and countless friends and Delawareans, I’ve been reminded of the power of one of my core values: the Golden Rule. It calls on us to treat others as we want to be treated. That means, to me, that all Americans ultimately should be free to marry the people they love and intend to share their lives with, regardless of their sexual orientation, and that’s why today, after a great deal of soul searching, I’m endorsing marriage equality.

This is the first Democratic flip that might be worth taking at face value rather than as a transparent, cynical electoral gambit to stay on the base’s good side. Carper had zero reason to hold out this long unless he was genuinely conflicted about it. The state hasn’t gone red in a presidential election since 1988; the vice president of the United States, who comes from Delaware, is already on record as supporting SSM; and Carper himself won reelection just last year by more than 35 points. He’s in less electoral danger than virtually anyone else in the Senate. He held out, presumably, because he’s part of the 65+ age demographic that’s most resistant to gay marriage, but given the political leanings of his state, he must have been getting the pro-SSM pitch from constituents for years now. They finally wore him down.

Speaking of blue-state Senators finally changing their mind, here’s Mark Kirk of Illinois becoming the second Republican in the caucus after Rob Portman to fully endorse gay marriage.

When I climbed the Capitol steps in January, I promised myself that I would return to the Senate with an open mind and greater respect for others.

Same-sex couples should have the right to civil marriage. Our time on this earth is limited, I know that better than most. Life comes down to who you love and who loves you back– government has no place in the middle.

His statement’s less explicitly religious than Carper’s but they’re similar in how they emphasize love over legalistic arguments about equality. Kirk was one of three Republicans I named in the initial post about Rob Portman as predictable flips on this issue if only because it’d cause a problem for him in his very Democratic home state in the general if he didn’t. (He’d already endorsed civil unions.) Collins and Murkowski were the other two, and although they’re still technically “evolving” they’ll be there soon enough. Kudos to alchemist19 for predicting that Kirk would be the next domino to fall among Senate Republicans.

Let’s make the new round of the pool a little harder. Name the next Democrat and Republican to flip. Collins and Murkowski don’t count; we’ve already declared them to be de facto flippers for pool purposes. I’ll stick with Bill Nelson, thereby ensuring that the next Democrat will be anybody but Bill Nelson, and I’ll take Kelly Ayotte on the GOP side. Exit question: Now that there are 50 Senators on record as supporting gay marriage, they’ll at least try to repeal DOMA next year if the Supreme Court doesn’t do it for them, no?